Piston ring



y 9, 1929- J. WILLIAMS ET AL 1.720.504

PISTON RING Filed Dec. 29, 1926 M0 J cki MZZa/ TQS, Judson z/ZZZLZLM.

JUIlElIFl' WTTJMMS AND ql'lU'Dl'dtlll' LLIAIMIS, OF PHILADELPHIA, PENNSYLVANIA.

PISTON RING.

Application filed. December 29, 1926. Serialll'o. la'lfl'fdl.

This invention relates to an improved piston ring and while being particularly designed for use in connection with internal combustion engines is, nevertheless, well n adapted for general application.

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The invention seeks, among other objects, to provide a ring which will conform to the contour of a worn cylinder and function efficiently therein, as well as a ring which will likewise function in an over-size cylinder even though the ring is of standard size as ordinarily perscribed for such cylinder.

A further object of the invention is to provide a ring which will function efficiently in a worn ring groove, which will tend to eliminate ring slap as well as piston slap and which will also tend to overcome oil pumping.

Another object of the invention is to provide a ring which will accommodate unvarying oil drainage by providing drainage passages of substantially fixed dimensions while, however, the use of sawed drainage slots will be avoided.

And the invention seeks as a still further object to provide a ring wherein each ring element used will provide a complete oil wipe to coact with the cylinder wall substan tially throughout its inner circumference.

Other objects of the invention not specifically mentioned in the foregoing will appear during the course of the following description.

Tn the drawings:

Figure l is a perspective view showing the elements of our improved piston ring disassembled but in proper relative position,

F ignre 2 is a side elevation greatly exaggerated to show the manner in which one of the ring elements is flexed to provide drainage passages,

Figure 3 is a detail section on the line 3-3 of Figure 93, L

Figure d is a detail section showing the use of but two of the ring elements, and

Figure 5 is a detail elevation showing the use of but a single ring element. 0 1

ln Figures 1, 2 and 3 of the drawings, we have shown the ring composed of a pair of like annular ring elements it], a third annular ring element 1.1 and an expander 12. However, we do not wish to be limited in th s respect since more than two of the eles l6 may be employed, or as will be "ated out detah, less two of said elements may be used and if desired the element 11 may be utilized alone. F urthermore, if the elements 10 and ll and expander 12 are considered as a set, two or more of said sets may, for instance, be utilized in a wide ring groove. Accordingly, the following description shall be considered as relating to one preferred embodiment of the invention and not as restricting us to the exact arrangement shown.

In producing the elements 10, a cylinder is formed by casting and saidelements cut from the cylinder in accordance with well known practice. Urdinarily, the outer circumference of the cylinder is machined or finished so that said elements are thus provided with a finished outer peripheral edge and, after being out, said elements are further finished on one side only to lie fiat against the top or bottom wall of a ring groove, as the case ma be. The elements 10 are concentrically ormed and are also initially dormant. Tn other words, said elements as formed have no tendency to enpand in diameter and preferably, said elements are each broken or snapped at a point in their circumference to provide a broken joint at the ring ends. Each of said ele ments may then, of course, be flexed and slipped over a piston into the desired ring groove thereof. V

The ring element ll is also preferably cut from a casting in the manner previously indicated with reference to the ring elements 10 and is broken in the same manner, so that said element may be manually applied about a piston. After being cut from the casting, but before the breaking thereof, the element 11 is machined on one side thereof to produce a plurality of upstanding spacing lugs 13 Y which, preferably, are equally spaced circuniferentially of said element. The ring element is then turned over and machined on its other side to produce a plurality of like equally spaced lugs 14c. The lugs 13 and 1d are of a width equal to the width of the ring element and attention is now directed to the fact that said lugs 13 are equally spaced circumferentially of said element with respect to the lugs ld. lln the present instance we have shown the use of three of the spacing lugs at each side of the ring element. llrliowever, a greater or less number of logs may be employed, as found most desirable.

The element ll,

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have shown the improved ring installed in the upper ring groove of a conventional piston 15, the views being greatly enlarged. Initially, the expander is applied over the upper end of the piston to lie in the bottom ofthe ring groove. One of the ring elements 10 is then slipped over the upper end of the piston into the ring groove to lie against the bottom wall thereof. The element 11 is then slipped over the upper end of the piston to lie against the element 10 first installed when the other ring element 10 is applied over the upper end of the piston to overlie the ring element 11. As will be observed, the ring elements 10 and 11 are of a combined ma or thickness to fit snugly in the ring groove and all of these elements are pressed outwardly by the expander 12 to coact with the cylinder wall throughout the inner circumference thereof. Each ring element thus provides a complete oil wipe. Furthermore, due to the constant tension of the expander against the inner peripheries of the ring elements, said elements will be caused to conform to an oversize cylinder or to the innercontour of a worn cylinder. This constant tension on the ring elements will also by reason of the fact that said elements fit snugly in the ring groove, tend to counteract piston slap. Attention is now directed to the fact that the lu s 13 coact with the lower ring element or spacing the element 11 upwardly with respect to the former element at spaced points, at which the element 11 more or less ti htly contacts the upper ring element, w ile the lugs 14 coact with the upper ring element for spacing the ring-elementfi 11 downwardly with respect to the upper element, at equidistant intermediate points, at which latter points the ring element 11 more or less tightly contacts the lower ring ele- 'ment. The ring element 11 is thus flexed to assume a sinusoidal shape and is firmly so held with the result that oil passages 16 are defined at opposite sides of each of the lugs 13 between the ring element 11 and the lower element 10 while like oil passages 17 are defined at opposite sides of each of the lugs 14 between t ering element 11 and the upper ring element 10. Ample provision is thus made for oil drainage through the ring and since, through employment of rigid spacing lugs upon the ring element 11, said element cannot be flexed to cause the flattening of the sinuous curve thereof, the dimensions of the passages 16 and 17 will be substantially fixed. Accordingly, thev ring will accommodate the drainage of oil in substantially unvarying volume. As will be appreciated, the ring element 11 being flexed will press the ring elements 10 tightly against the top and bottom walls of the ring groove so that ring slap will be obviated and since the expander 12 will cause spreading of the ends of said ring elements, the lugs 13 and 14 are each of a length greater than the maximum length of the gap that would occur between the ends of either of the ring elements 10 so that no one of said lugs 13 and 14 can drop between the ends of either the upper or lower element 10, as the case may be, should said elements be caused to creep with respect to each other.

In Figure 4 of the drawings we have shown the use of one of the ring elements 10 and the ring element 11 in the narrow ring groove 18 of a piston 19. An expander 20 like the expander 12 is employed with the exception that the expander 20 is narrower.

In Figure 5- we have shown the use of the ringelement 11 alone in a very narrow ring groove 21 of a piston 22. An expander 23 like the expander 12 is employed with the exception that the expander 23 is much narrower.

Having thus described the invention, what we claim is:

A set of piston rings consisting of separate inner, outer and intermediate cast metal rings, the said rings being of substantially the same thickness and each of greater width than thickness, the inner and outer rings each being flat and of an even thickness throughout its circumference and the intermediate ring being also normally flat and of an even thickness throughout it's s prof entire circumference and having lu jecting from its opposed faces, the ugs of one face being in staggered relation to the lugs of the other face and spaced therefrom a sufiicient distance to cause the intermediate ring to be flexed circumferentially when the rin s are placed in a ring groove of a piston wit the inner and outer rings pressing against said lugs.

In testimony whereof we afiix our signatures.

JOHN WILLIAMS. [L.S.] J UDSON WILLIAMS. [1.. s.] 

